Before you start egg should be on room temperature, if the egg is just our from the refrigerator you can rinse them or put them on a bowl with water.
Soft boiled: 2 minutes
The white is solid, but the yolk is still runny. Serve in an egg cup for breakfast. Use the side of a small spoon to crack and remove the pointed end of the egg, making a hole in the shell large enough to fit the spoon. Or use egg scissors, if you have them.
Medium boiled: 4-1/2 minutes
The yolk is solid but still dark orange-yellow, moist, and dense in the middle. Beautiful and delicious quartered on a salad.
Hard boiled: 8 minutes
The yolk is completely solid, light yellow, and crumbly, with no sign of the telltale green or gray ring around the yolk that’s caused by overcooking. Perfect for egg salad or deviled eggs.
Credits to: finecooking.com